Very thin interior wall

[Anna Kettle]

I have allocated a space for a shower-loo-sink room but what I'd _really_ like is to squeeze a separate loo-sink into the space as well. After lots of entertainment as I drew the layout on a large sheet of white paper and walked around to make sure that there is enough space to fit it all in, the answer is yes it will fit ...

... if I make the wall between the shower-loo-sink and the loo-sink out of something much thinner than a normal stud wall. I'm thinking of using 22mm blockboard faced with 9mm plasterboard on one side and faced with a wall of the shower on the other side.

I'm planning for the shower to be "Steam cabin" Screwfix 83798 so the shower wall will be a sheet of plastic

Two questions ...

- Has anyone used one of these steam cabins or seen them in the sheds? Are they the bees knees or a heap of tat?

- Will the blockboard/plasterboard wall be good and rigid and will it be at least reasonable for sound dampening? The wall is only 1.3m long. Would some other material like plywood be better? Comments please

Anna

[Mary Fisher]

PLASTERBOARD???

:-)

You're the expert!and will it

Mary

[.]

never used one but they are a right bugger to install, allow at least a weekend (fri sat sun) using two experienced people but, really, allow a week all in, for building work, plumbing in and out, electrics etc. if you are doing it yourself.

3 x 2 cls stud wall would be strong enough and if you complete the wall with kingspan/marmox infill it certainly would be soundproof. you could skin the walls with 4mm ply and decorate over it, would be really strong.

hth

[Ian Stirling]

Mock it up with a stool/boxes, to see if you can actually physically get round the area.

IMO, this will be fine. It will be marginally noisier, and slightly colder in use than a 'proper' wall, but...

[Phil L]

Have you taken into account door openings?

The thing is, what's the blockboard going to be fixed to? - how is going to stay upright?

- you could fix it to the ceiling timbers, but this would mean removing a section of the ceiling, unless it's upstairs, then you could access via the loft, if it's feasable...if you have fathomed a way of fixing the blockboard upright, then yes, a 9mm PB will suffice, although you will need short screws, 20mm if possible

it will be as soundproof as you can get for a 34mm wall, IE not very, but considering the spaces involved, it's unlikely to be much of a problem, unless you intend having parties in the steamroom.

[EricP]

Go have a look at breeze blocks at your builders merchants. They are large, very light and quite cheap.

A wall can be built quickly with them and it will be quite solid and thin.

[Phil L]

They are 100mm wide Eric, she needs it to be 35mm max...studding also ends up at around 100mm once skimmed

[meow2222]

couple of observations: sheet ply is stronger than blockboard ply is stronger than plasterboard, which would add sod all to the stiffness of the wall. Lining paper will make ply into a nice paintable surface, and is

[dennis]

I would think about fixing some angle metal to the floor and ceiling and screwing 12mm plywood to either side. I think it will be better noise insulation than blockboard and plasterboard and it will be a lot stronger.

Is there any need for fire resistance?

[Pete C]

Hi,

You could use two layers of 'Fermacell' cement board with a small gap in between:

Like:

Maybe a thin lath in the middle of the 1.3m wall instead of a stud.

cheers, Pete.

[The Natural Philosopher]

I'd use either 19mm ply or MDF. Both make reasonable small walls. MDF needs no surface treatment..juts caulk where it meets stuff (leave a little gap) as it shrinks a tad eventually. Then paint with emulsion straight. Sand after first coat. Tile straight onto it.

Sound rejection of any solid thin wall will not be great. My guess is

20-30dB versus 50-60 for a proper stud..

[Ian Stirling]

I just burst out laughing imagining breeze blocks the size of lego.

[Anna Kettle]

If you have any handy hints for fitting this particular shower that you can pass on to me then I'd appreciate them. I expect they are a pig to fit but then I would expect it to take me a week to install a normal shower and at least there is no tiling with this one! I must try to find one of these showers to actually look at before I buy. Partly to make sure its of good sturdy construction and partly to find out where the water and electric feeds are. In such a confined space its important that I do that at the planning stage. I suspect that the main reason for choosing it is so I can singi along to thje radio as I shower! (Expensive radio)

Ian and Phil: Yes I've d>I would think about fixing some angle metal to the floor and ceiling and

Thats an interesting idea and it so happens that I have several lengths of quality angle iron sitting in the shed looking for a use

I hadnt thought about that. Are there any regulati>sheet ply is stronger than blockboard

Right, lining paper it is!

So I'm looking at angle iron holding a paper/ply/foam/ply sandwich. Sounds good

Yes fixing will be OK cos conveniently it all lines up nicely with the joists. Oh the joy of new build

Fermacell sheets are 12.5mm so yes thats another >I'd use either 19mm ply or MDF. Both make reasonable small walls. MDF

Or an MDF/foam/mdf sandwich with no lining paper needed

Worth it I think for the advantage of the extra loo

Anna

[Cicero]

===============================

Your target thickness of 31mm can be achieved as follows. A sandwich made up from 6mm ply + 30mm PAR timber + 6mm ply. The 6mm ply layers to be routered into the 30mm timber leaving a cavity of 18mm. The cavity to be filled with 25mm thick polystyrene (Wickes etc) which will compress into the 18mm cavity. This will make a very rigid panel with adequate sound proofing.

This is a very similar construction to those 'Sapele' doors which were so prevalent a few years ago and which are about 34mm thick. It might be possible to use actual doors of this type to make your panel if your panel size matches the size of a standard door.

The whole structure to be supported by angle brackets at top, bottom and wall.

Cic.

[EricP]

My breeze walls upstairs are all the thickness of a socket box. Put one in a wall and the back of the box is flush with the plaster in the next room. (Much to my disgust when I did one.)

That's the sort of block I was thinking of. Sorry to cause confusion.

[Mary Fisher]

You see how highly I regard you!

Mary

[Ian Stirling]

I really don't think it will compress. At the least, you're going to get severe bowing, and unless the PAR timbber is every 6", it's just going to pop off the fixings.

The trivial way to thickness polystyrene is to put down a couple of battens, and run a hot wire between them, but a bow-saw, with the blade at a right angle works just fine, though messily. (glue the polystyrene down first, or be careful about it pulling up.

[meow2222]

30mm framing will be lousy, and give almost no soundproofing. Yes it'll work, but sheet material will give much more strength than framework only, hence less sound transmission.

The sapele doors are cardboard interior with wood veneer finish, plus strips of wood for the 2 side edges, and theyre a good idea if you're ok with the finish and the lack of soundproofing. ISTR Ikea make tables out of them.

NT

[Cicero]

================================ As you imply, compressing by 7mm might be difficult - a case of trial and error really. Given that polystyrene is always messy to cut to size a simple way to reduce thickness (if necessary) by a few millimetres is to draw a large sharp saw across it as if using a spoke shave. Very messy but effective.

Cic.

[Ian Stirling]

True, but in this case it's really wanted to be semi-structural, so would need to contact either side, this is going to be moderately difficult freehand, though I don't see why it wouldn't work with a couple of battens to set the depth. probably better than the 'saw it' solution, for a few reasons.